This
is an exclusively Tibetan Buddhist praying instrument
which always bears the mystical word 'OM MANI PADME
HUM' [Om the Jewel in the Lotus Hum] numbering six
syllables in the mantra of Avalokitesvara. The syllables
are carved outside the wheel as well as kept inside the
wheel printed in the paper in numerous numbers. It is
generally made of a cylindrical body of repoussé
metal, penetrated along its axis by a wooden or metal
handle. The cylinder can turn around the handle, with
a slight rotation of the wrist, thanks to a cord or ballasted
chain, which keeps it in movement. Inside this cylinder,
written on paper or skin, are esoteric texts, usually
invocations (dharani or mantra), the most common
being that of Avalokitesvara.

These
prayer wheels may be small and carried by pilgrims,
or larger and fixed to the gates of monasteries or around
stupas and chortens. Each turn of the cylinder generates
as much merit as the reading of the sutra or the formula
enclosed therein. All these objects are also called
chhos-hkor in Tibetan, 'Wheel of the Law'. Some
are very large and, enclosed in small structures, turn
under the action of a 'mill' driven by water.